09- Occlusion in prosthodontics- occlusal correction.ppt

Occlusion in prosthodontics-
Denture Placement and Occlusion Correction

1. 9- Denture Placement and Occlusion Correction

2. Dr. Amal Fathy Kaddah Professor of Prosthodontic, Faculty of Dentistry, Cairo University Denture Placement & Occlusion Correction

3. Clinical errors Technical errors Inherent deficiencies in the material itself Introduction Causes of Denture Errors

4. Errors in impressions Ill-fitting trial denture bases Inaccurate jaw relation records Errors during transfer of the records to articulator Incorrect arrangement of posterior teeth Clinical Errors

5. Processing and Technical faults Distortion due to improper flasking Failure to close flask completely Too much pressure while closing the flask from the flask press. Tooth movement during flasking or packing Failure to cool flask before deflasking Warpage due to overheating during polishing

6. Technical discrepancies could be due to: 1- Dimensional Changes in the wax due to variation in temperature. 2- Expansion of the investing material during the processing (plaster and dental stone ). 3- Errors which may occur during packing of acrylic resin. 4- Changes in the acrylic resin material during processing procedures (polymerization shrinkage).

7. Types of Occlusal Errors C.O. not coincide with C.R. Premature contact (high point) in one or both sides Uneven distribution of occlusal contacts Eccentric movement prematurities (protrusive & lateral)

8. Why is it difficult to detect occlusal errors in the mouth? *Shifting of denture bases, incorrect closure by patient * Resiliency of the Soft tissue * Negative attitude (assume an error exists and try to find it)

9. How can you Detect Occlusal Errors ? Denture dislodges (instability) or shifts when patient occludes Patient complains of pain beneath denture bases >> worst by time Sliding of denture bases or uneven pressure caused by faulty occlusion can lead to ulceration of mucosa.

10. Steps of Occlusal Correction

11. TRIAL INSERTION STAGE

12. Cervical necks tilt posteriorly from the central incisor to the canine

13. The appropriate Curve of Spee should be incorporated into the setup. Make sure the posterior mandibular teeth are centered over the ridge

14. The plane of occlusion should be parallel to the body of the mandible and extends from the incisal edges of the central incisors and the middle portion of the retromolar pads bilaterally.

15. TRIAL INSERTION STAGE

16. TRIAL INSERTION STAGE

17. Finalize Wax up

18. Fabrication of Occlusal index for clinical remounting At the end of the try in stage where the dentist and patient are both satisfied. This is a time save procedure for you because you do not have to make a new facebow record at the time of delivery.

19. Place the Facebow remount jig on the lower member of the articulator. Verify that the incisal guide pin is set at zero. Allow plaster index to completely set. Verify that the maxillary teeth can be repositioned into the indentations . Occlusal index for clinical remounting

20. To save the position of the maxillary cast No need for face bow record in the clinical remounting step

21. Flasking for Processing

22. - During deflasking : be careful to preserve the cast, also do not left or remove the denture from the casts Clean the denture and cast from plaster. Remove any stone or bubbles from the exposed acrylic resin and from the occlusal surfaces of the teeth. Remove any particles of stone from the base of the cast and index grooves. Using a stiff brush, soap and water clean the denture and cast before starting the laboratory remount

23. Dentures being re-mounted on the original articulator and adjustments carried out to provide correct articulation (Laboratory Remounting).

24. Laboratory Remounting

25. * Laboratory Remounting Carried out, after defalsking and before polishing of the denture, (before the dentures are delivered to the patient), for perfection of occlusion. Occlusal discrepancies may result from technical discrepancies.

26. Purpose To correct errors in occlusion that have occurred during processing To return dentures to the correct vertical dimension To obtain a smooth even contact of the teeth in centric and eccentric positions .

27. Disadvantages Cannot correct errors made while recording jaw relations Cannot correct errors made while mounting the casts on the articulator Does not compensate changes caused by settling of the denture bases

28. The processed denture on the master cast is repositioned to its old position on the articulator by means of remounting indices made in the master cast before mounting .

29. Remount and Adjust for Processing Errors

30. The condylar elements of the articulator are locked in the centric relation and the articulator is closed. The incisal guide pin not contact the incisal guide table, The occlusal vertical dimension has been changed and must be re-established.

31. Place red articulating paper between the teeth and gently tap the teeth together in centric occlusion.

32. The adjustment in centric occlusal position should be stopped when widespread Contacts are produced

33. The incisal guide pin usually stays in contact with the incisal guide table.

34. The adjustment in eccentric occlusal positions

35. The adjustment in eccentric occlusal positions should be stopped when widespread Contacts are produced and the incisal guide pin usually stays in contact with the incisal guide table.

36. The Aim of Laboratory Remounting The prematurities are ground until multiple, uniformly distributed and even contacts are obtained bilaterally The incisal guide pin stays in contact the incisal guide table

37. Finishing and Polishing

38. COMPLETE DENTURE INSERTION (DELIVERY)

39. a . Adjustment of Processing Error . b . Finishing and Polishing of Denture . 1. PRE‑INSERTION PREPARATION 2. INSERTION VISIT 1 . Re‑examine dentures and foundation tissues. 2 . Insert each denture independently. 3 . Occlusal equilibration to be accomplished at this time. a . Clinical Remount of the upper cast. b . Interocclusal records ‑ waxes . c . Remount the lower denture.

40. Correcting occlusal errors in patient's mouth Articulating paper in the mouth . Not give accurate indication due to the resiliency of the supporting tissues Adhesive Wax

41. or

42. CLINICAL REMOUNT AND OCCLUSAL REFINEMENTS

43. Clinical remount Dentures should be remounted with new records obtained from the patients Mount the upper cast according to a face-bow record or occlusal index * and Mount the lower cast according to a new centric relation record.

44. Advantages of Clinical Remounting with New Interocclusal Records * Less chair side time Corrections away from the patient’s view No saliva which makes detection by articulating paper difficult No shifting of dentures or incorrect closure by patient

45. The Aim of Clinical Remounting The prematurities are ground until multiple, uniformly distributed and even contacts are obtained bilaterally

46. Clinical remounting is currently the most commonly preferred method of occlusal correction

47. Fabrication of Remount casts at the time of delivery Block out undercut areas in the tissue surfaces before pouring the plaster

48. Clinical Remounting Procedure Ask patient to bite on cotton rolls for 10 min. Guide mandible into CR several times. Bite registration material is placed on the posterior teeth of the mandibular denture

49. Clinical Remounting Procedure Guide mandible into CR Obtain the new interocclusal record of C.R. using your recording medium of choice, making sure that the teeth do not touch . ???

50. Try in??????

51. Do I need New Face bow RECORD????????? Remount upper denture using remounting jig Clinical Remounting Procedure

52. Mounting the lower cast with new CJRR Make sure that the denture bases are not contacting posteriorly.

53. I. Selective grinding II. Milling The procedures of Perfection of occlusion

54. Selective Spot Grinding * Reducing premature contacting surfaces, so that an equal pressure exists at all points with no interference

55. The buccal cusps of the mandibular posterior teeth and lingual cusps of maxillary teeth are called supporting cusps. These cusps occlude in central fossa and maintain the occlusal vertical height. They also called centric cusps and holding cusps . Supporting cusp or Functional Cusp The lingual cusps of mandibular posterior teeth and buccal cusps of the maxillary posterior teeth called guiding cusps. They guide the mandible in lateral movements. Non Functional Cusps

56. Note that the stamp cusps (those fitting into the central portion of the opposing teeth) compromise 60% of the total faciolingual tooth dimension.

57. Basic Tooth Positions Balancing Contacts Centric Occlusion Working Contacts Ideally all holding cusps * of the maxillary and mandibular posterior teeth will make simultaneous contacts.

58. How to Recognize Premature Contacts? A dark ring with a light center usually denotes a premature contact

59. You should distinguish between marks made by normal occlusal contacts and those of premature contacts How to Recognize Premature Contacts? Articulating paper should not be reused many times and should be changed often.

60. Selective Spot Grinding Make grinding until even (same intensity), stable, and multiple marks spread over wide area in both sides

61. *Eliminating Occlusal Errors (selective grinding) Procedures of

62. The sequence of steps should be as follows Restore the vertical dimension Re-establishment of C.O. Correction of working side occlusal errors. Correction of balancing side errors. Correction of protrusive relation.

63. The condylar elements of the articulator are locked in the centric relation and the articulator is closed. Grind the teeth with small diamond stones. Use red articulating paper to mark the area of premature contacts for making centric occlusion and blue articulating paper for the eccentric movements 1. Adjust the articulator to the proper setting

64. Lock the upper arm of the articulator in centric relation. Check the occlusion by opening and closing the articulator. Place red articulating paper between the teeth and gently tap the teeth together in centric occlusion.

65. 2. Establish the occlusal vertical dimension in centric: Occlusal VD is maintained by occlusion of palatal upper cusp and buccal lower cusp (in normal occlusion) ( Supporting cusps)

66. If the cusp is high in centric and eccentric relation, reduce cusp. If the cusp is high in centric but not eccentric, deepen fossa.

67. Correction of occlusion done by reducing buccal incline of upper Lingual cusp and Lingual incline of lower buccal cusp or deepening their corresponding fossae p B

68. Do not grind the cusp tips unless it is high in every excursion, but rather reduce the fossa or inclined plane of the cusp. 3- Re-establishment of C.O .

69. Problem : Teeth too nearly tip to tip (If insufficient overjet) Solution : Grind Inclines - Grind the inner inclines of upper buccal & lower lingual Cusps. - Grind lingual incline of upper lingual cusps. - Grind buccal incline of lower buccal cusps. So that the cusp tips contact the central fossae. The cusp tips should not be shortened. Re-establishment of CO

70. Problem: Too much horizontal overlap (upper teeth too far buccaly to lower ones) Solution : . Broaden central fossae Grind the inner inclines of upper lingual cusps & lower Buccal cusps. Re-establishment of CO The cusp tips should not be shortened .

71. The adjustment in centric occlusal position should be stopped when widespread Contacts are produced

72. Reduce the teeth until the incisal pin touches the incisal guide table and uniform contact exists on all posterior teeth. Anterior teeth should not touch in centric occlusion.

73. After the CO re-establishment DO NOT Reduce maxillary lingual cusps. DO NOT Reduce mandibular buccal cusps. These cusps are essential to maintain the recorded vertical dimension DO NOT Deepen the fossae.

74. Loosen the locks on the condylar elements and move the denture in eccentric movements. Using blue articulating paper between the teeth. 4. Refine occlusion in eccentric

75. The adjustment in eccentric occlusal positions

76. The adjustment in eccentric occlusal positions should be stopped when widespread Contacts are produced and the incisal guide pin usually stays in contact with the incisal guide table.

77. If the cusp contacts prematurely on closure as before, but is not premature in lateral excursions, the fossa is deepened Prematurely contacts in centric and in lateral excursions, the cusp is reduced in height.

78. a- Lateral movement: i . On the working side: Follow "Bull rule" of reducing buccal upper and lingual lower cusp inclines. b. Protrusive movement: Bull rule does not work. Reduce interceptive cusp as shown by the carbon paper. ii. On the balancing side: Reduce distal inclines of maxillary cusp and mesial inclines of mandibular cusps

79. Reduce lingual inclines of buccal cusps of upper teeth. Reduce buccal inclines of lingual cusps of lower teeth . ON WORKING SIDE ONLY!!! i- "Bull rule on the working side "

80. Problem: Buccal and lingual cusps too long. "Bull rule on the working side "

81. Occurs between the lingual upper and buccal lower supporting cusps Which are the functional cusps Adjustment Rule : Buccl inclines of the lingual upper cusps . lingual inclines of the buccal lower cusps . LUBL ii. Correction of Balancing Side interferences

82. ii. Correction of Balancing Side Errors Decide which supporting cusp maintains CO and reduce its opponent.

83. If interference exists on the balancing side Grind the lingual incline of the mandibular buccal cusp. It is a centric holding cusp so grind carefully and do not reduce the cusp tip. Correction of Balancing Side interferences

84. a. If the anterior teeth have heavy contact with no contact on the posterior teeth grind the labial surface of the lower anterior and the palatal surface of the upper anteriors . b. If heavy posterior contact exists with no anterior contact reduce the distal inclines of the maxillary cusps and the mesial inclines of the mandibular cusps. b- Correction of Protrusive Relation

85. In protrusive excursion, premature contacts are eliminated by grinding the distal facing inclines of upper teeth and mesial facing inclines of lower teeth DUML Adjustment Rule :

86. Proceed with selective grinding until you get balance at centric contact and occlusal harmony in eccentric movements

87. Briefly BULL rule in: -Working side interferences. LUBL rule in: -Non-working side interferences. DUML rule in: -Protrusive interferences.

88. Direct Intraoral Correction Requires a lot of patient cooperation Patient should have good neuromuscular control Saliva Inaccurate closure by patient Misleading due to resiliency of tissues and shifting of denture bases Disadvantages

89. Direct Intraoral Correction Check for the coincides of maximum intercuspation with centric relation position, and whether the vertical dimension of occlusion is unchanged or not. Only small discrepancies in maximum intercuspation, can be adjusted following the same rules as for correcting occlusal errors on the articulator.

90. Rules for selective grinding: Never grind a centric cusp tip unless it contacts prematurely in all excursions of the mandible. Always grind the opposing fossa or marginal ridges where the centric holding cusps occlude Utilize the BULL rule when perfecting working occlusion , For interference in the posterior teeth reduce the upper buccal cusp slopes and the lower lingual cusp slopes. When grinding to perfect balancing occlusion never grind the interfering cusp tips but grind the cusp inclines. In correcting protrusive interference in the anterior teeth grind on the labial portion of the incisal edges of the lower teeth and the lingual portion (palatal surfaces) of the upper teeth. In protrusive balance, the anterior teeth should make incisal edge contact at the same time that the tips of the buccal and lingual cusps of the posterior teeth contact.

91. Balance occlusion in Working side, Balancing side, Protrusive position

92. II- Digital methods Digital technology helps clinicians to identify premature contacts, high forces, Timing and interrelationship of occlusal surfaces.

93. T-Scan is an objective assessment tool used to evaluate the occlusion of a patient. Unlike articulating paper, which can only determine location , T-Scan can identify both force and timing, two of the most fundamental parameters for measuring occlusion.

94. II. Milling XXX A small amount of carborubdum abrasive paste is placed over the lower teeth and the articulator is closed in centric position. Several movements are made from centric into each eccentric position to eliminate any slight interference

95. Remounting has the following advantages 1- Reduce patient's participation. 2- Allow for better visualization. 3- Provides a stable working foundation. 4- More accurate markings with the articulating paper in absence of saliva .

96. 3. POSTINSERTION CARE 1 . First appointment within 48 hours of delivery . 2 . Second appointment within 3 days . 3 . Third appointment within 1 week of 2nd visit . 4. CASE COMPLETION 1 . Patient able to masticate food . 2 . P atient should present a normal individual appearance . 3 . Patient should be able to speak distinctly . 4 . Patient should experience oral comfort . 5 . Patient should be educated as to the need for periodic examination . 5. RECALL

97. References Boucher's prosthodontics treatment for edentulous patients. Twelfth Edition. Chapter 20. Complete Denture Prosthodontics, 1 st Edition, 2006 by John Joy Manappallil , chapter 19 Dalhousie continual education Denture placement & patient education - dr.Rola shadid https://drrolashadid.Weebly.Com/uploads/1/4/9/4/14946992/lecture_10_1.Ppt Https://wsdav6.Squarespace.Com/s/i-hate_love-complete-dentures-ronnie-schnell.Pdf John Beumer III, DDS, MS: 24. Refine Denture Setup Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry UCLA School of Dentistry Washington state dental association's 2015 pacific ... - WSDA

98. THANK YOU